1. Technical Field of the Invention
The present invention relates to a method of fabricating a semiconductor device. Also, the present invention relates to a semiconductor device fabricated by the above method. More particularly, the present invention relates to a simplification of a process of fabricating a semiconductor device.
2. Description of the Related Art
Recently, the size of a semiconductor device has been greatly reduced and its structure has been highly integrated. In accordance with that, a method of wiring of Dual-Damascene structure is known, in which upper metal wires 8a and 8b are embedded in an insulating layer as shown in FIG. 7. When the Dual-Damascene structure is adopted, it becomes possible to form wiring made of a material such as copper, which is difficult to be etched.
Referring to FIGS. 8A to 8C, a method of fabricating a wiring of the Dual-Damascene structure will be explained below. First, a resist pattern used for forming contact holes is formed on the SiO.sub.2 layer 2 as an insulating film and the SiO.sub.2 layer 2 is selectively etched to form contact holes. Successively, a resist pattern used for forming grooves is formed on the SiO.sub.2 layer 2 and the SiO.sub.2 layer 2 is selectively etched to form grooves. Due to the foregoing, as shown in FIG. 8A, a groove 6a for the first wiring section, contact hole 4a, groove 6b for the second wiring section and contact hole 4b are formed. FIG. 8B is a view taken in the direction of arrow A in FIG. 8A.
Then, a copper film 11 is formed all over the surface by the method of plating. Due to the foregoing, the copper film is embedded in the grooves 6 and the contact holes 4, and an upper surface of the SiO.sub.2 layer 2 is covered with the copper film 11 as shown in FIG. 8C.
Next, copper film formed on portions except for in the grooves 6 and the contact holes 4 is removed by the method of chemical mechanical polishing (CMP method). Due to the foregoing, the first wiring section 18 and the second wiring section 19 are insulated from each other as shown in FIG. 7.
However, according to the above fabricating method, the following problems may be encountered. In order to insulate the first wiring section 18 and the second wiring section 19 from each other, it is indispensable to use the CMP method. Therefore, it is necessary to provide a device of CMP. Especially, when the CMP method is adopted, it is necessary to appropriately select chemicals and abrasive materials. Accordingly, when a wiring layer is made of a new metal, much time and expense are required for the investigation.